The present invention relates generally to improvements in vehicle safety or seat belt systems and it relates particularly to an improved automatic locking system for vehicle safety belt rewinding reels.
The conventional vehicle safety belt includes a suitably anchored reel about which the belt is wound and which is biased by a rewind spring to a belt retracted condition. In normal use the belt is withdrawn from the reel for its full length and the free end of the belt is coupled by a tongue and buckle arrangement to the opposite side of the seat to secure the occupant in a restrained condition to the seat. The belt is of adjustable length to accommodate occupants of different girths or sizes. The aforesaid conventional safety belt mechanism possesses numerous drawbacks. Among these is the requirement of manually adjusting the length of the seat belt to the size of the respective seat occupant. Another important disadvantage of the conventional seat belt mechanism is that it greatly restricts the movements of the restrained seat occupant during normal operation of the vehicle thereby interferring with the optimum and efficient control of the vehicle by the driver causing a high degree of discomfort.
In order to overcome the above drawbacks of the conventional reel retracted safety belt system, many types of retractor reel systems have been proposed from which the belt may be normally continuously withdrawn but is braked in response to an inertia type sensing mechanism. While these systems possess many advantages, they are frequently unreliable since the reel braking is either of too short duration or is maintained for an indefinite period and they otherwise leave much to be desired.